📝 chore(deploy_gh-pages.yml): add GitHub Actions workflow to deploy to GitHub Pages

This commit adds a new GitHub Actions workflow file, `deploy_gh-pages.yml`, which is responsible for deploying the project to GitHub Pages. The workflow is triggered on pushes to the `lf-docs-fix` branch.

The workflow consists of the following steps:
1. Checkout the repository
2. Set up Node.js environment with version 18 and npm caching
3. Install dependencies for the documentation
4. Build the website
5. Deploy the built website to GitHub Pages using the `peaceiris/actions-gh-pages` action
   - The deployment is done to the `gh-pages` branch
   - The build output is published from the `./docs/build` directory
   - The commit authorship is assigned to the official GH-Actions bot

This workflow enables automatic deployment of the documentation to GitHub Pages whenever changes are pushed to the `lf-docs-fix` branch.